The invention relates to improvements in apparatus for removing contaminants (especially moisture) from the sides of running webs. More particularly, the invention relates to improvements in apparatus which can be used with advantage as a means for wiping contaminants off one or both sides of running webs of photographic paper or another wet processed photosensitive material. Still more particularly, the invention relates to improvements in apparatus of the type disclosed, for example, in commonly owned U.S. Pat. No. 4,793,073 to Leuchter.
It is customary to transport exposed webs of photographic paper through a series of baths wherein the sides of the running web are contacted by various fluids. For example, a web of photographic paper will normally advance through a developing bath, thereupon through a fixing bath, then through a rinsing bath and thereafter through one or more drying chambers. In order to prevent the web from entraining large quantities of a liquid from a preceding bath into the next-following bath, or from the last bath into the drying chamber, it is customary to advance the web through apparatus which are designed to wipe the sides of the web clean, i.e., to strip off at least a high percentage of moisture between two successive baths or between the last bath and the next-following treating station. In the absence of such undertakings, the fixing bath would be rapidly mixed with a progressively increasing percentage of developing solution, and the rinsing bath would receive a progressively increasing percentage of fixing solution. Moreover, the web would be likely to entrain a large quantity of rinsing liquid (e.g., water) into the adjacent drying station. All this would cause numerous problems necessitating frequent stoppages of the developing machine and resulting in a reduction of the quality of customer prints which are obtained as a result of subdivision of properly exposed and developed webs of photographic paper.
Published German patent application No. 20 48 902 describes a wiping or moisture removing apparatus which employs one or more stripping or wiping lips of rubber or other suitable elastomeric material. A drawback of such apparatus is that the relatively sharp marginal portions of the running webs rapidly remove substantial quantities of material from the adjacent portions of the lip or lips so that the lips are provided with notches which permit streaks of moisture to bypass the wiping apparatus and to enter the next bath or the drying station following the last bath. The situation is aggravated if a relatively narrow web is followed by a wider web because the notches which were formed by the marginal portions of a preceding (narrower) web are then adjacent the picture bearing portions of the next-following wider web or webs to seriously affect the quality of the pictures by changing the concentration of various substances in the next-following baths or by permitting streaks of moisture to overlie the picture bearing parts in the drying chamber or chambers. The situation is analogous if a lip which is already notched by a relatively narrow web is thereupon used to wipe excess moisture off the same web after the web has changed its path by having moved sideways so that one of its picture bearing portions entrains one or more streaks of liquid. The presence of excess moisture on those portions of a web of developed photographic paper which have advanced beyond the last bath and into the drying station or stations is particularly likely to adversely affect the quality of customer prints.